Signal-controlling means



C. T. MAGILL Sept. 30, 1930.

SIGNAL CONTROLLING MEANS Original Filed July 14, 1927 J W m 4 6% M Ad @WY m 1 1 lb lli ll/ll/rldr/lAr/A m. 4 1 2 a g A J F m 0 r 1 2 E a a I w/a g mm a Patented Sept. 30, .1930

UNITED STATE s, PATENT ori ice CHARLES T. MAGILL, OF CLARKDALE, ARIZONASIGNAL-CONTROLLING MEANS Original application filed my 14,4927, SerialNo. 205,675. Divided and this'application filed May 28,

' 1928. Serial No. 281,334.

This application is a division of my pending U. S. application SerialNo. 205,67 5, filed July 1 1, 1927.

The parentapplication relates to a sig-' 5 calling system designedprimarily for use on automobiles to give Warning to following drivers,that reduction in speed is being made.

The present application is devoted to con trolling-means for the signal,specifically to a signal-operating switch, and it is the object of suchinvention to provide a switch structurecf exceptionally simple andinexpensive nature, yet one which will be highly efficient and desirableand will be sensitive to slight reduction pressure.

While the invention is primarily intended for use in an automobile speedreduction signal, it is to be understood that it is usable to equaladvantage in other fields, for maintaining a signal in oneconditionunder certain circumstances, and for effecting operation of the signalto give a different reading or indication, under other circumstances.

lVith the foregoing in view, the invention resides in the novel subjectmatter hereinafter described and claimed, description being accomplishedby reference to the accompanying drawing.

Fig. 1 is a vertical sectional View through a signal controlling meansconstructed in accordance with the present invention.

Fig. 2 is an enlarged vertical sectional view through the centralportion of the structure shown in 1.

Fig. 3 is a-horizontal sectional view on line 33 of Fig. 2.

In the form of construction shown in the drawing above brieflydescribed, the control means embodies two axially alined cylinders 16 17having a threaded connection 18 with each other at their inner ends,said inner end of the cylinder 16 being enlarged internally to provide aspace 19 within which certain contacts operate. A double ended plunger21 its opposite ends mounted in the cylinders 1-617 respectively, andone or both ends of this plunger may be provided with packing rings suchas 22. Cylinder 16 is provided with a pressure inlet 23 for connectionby a pipe or the like 24 with any pressure-containing system or chamberwhose varying pressure is to be relied upon to operate thesignal-controlling means. \Vhenthis pressure is sufficiently great,-itforces the plunger 21 toward the cylinder 17 to a greater or lesserextent,accordingto the strength of such pressure.v As lunger 21 movesfurther into the cylinder 1?, it compresses air in the latter, the airpressure thus counterbalancing the pressure in the cylinder 16 andserving to hold the plunger 20 against downward movement as long assufficient pressure exists in said cylinder 16. As soon as this pressureis reduced however, the air pressure in the cylin der 17 forces theplunger 21 further into the cylinder 16. These pressure-effectedmovements of the plunger 21, are relied upon to control a signalcircuit, of suitable nature, but as this circuit and thesignal thereofconstitute no parts of the present invention, they have beenomitted'from the drawing.

Binding posts 24 are provided for currentconducting wires, said postspassin through the enlarged inner end of the cy inder 16 andbeinginsulated therefrom. The inner ends of these binding posts carrycontacts 26 of any desired form. These contacts are in the pathof amovable signal-controlling or switch member 27 within the chamber. 19,said switch member having a frictional engagement with the plunger 21.Preferably, this switch member 27 is in the form of a metallic shellsurrounding an insulating ring 28 whichsurrounds the plunger, said shelland ring being split as at 29 in Fig. 3 and being of self-contractingnature to establish a frictional or slip connection between member 27'and plunger 21.

When there is practically no pressure in the lower cylinder 17, theswitch member 27 engages the contacts 26 as shown in Figs. 1 and 2, andthe signal circuit is then closed. Upon increase in pressure in thecylinder 16 however, such pressure elevates the plunger 20, causing thering 28 to elevate the entire switch member 27 out of engagement withthe contacts 26 so that the signal circuit will be broken. Uponadditional increase of pressure in the cylinder 16, plunger 21 is forcedfurtherupward and during such movement,

" cent of plunger 21, comes into play to depress this plunger. Thisdescent of plunger '21 brings switch member 27' against the con .tacts26, affecting the signal -circuit. in the desired way.

Preferably, the contacts 26 are spaced apart about 120, and a-deadcontact 26 is disposed between them. "ment prevents the contacts fromhaving any tendency tocant the ring .528 'on the plunger '21 withdangerof binding.

This arrange- -Excellent results areobtainableffrom the generalconstruction shown and described, and such construction is thereforepreferably followed. yl-lowever, 1t51s togbe understood that within thescope of the invention .as claimed, variations'mayzbemade.

I'claim:- I .1. Ina 'signal'controlling ineans,:a'prcs- "sure controlledsignal 'operatingmember, a pressure'chamber for effecting movement'otsaid member in onedirection, 'and'a second chamber in whichairiscompressed'bymovement of said member in." SZLICLOHG" direction,

the air'so'compressed serving'to move said I member 111theotherdirectlon upon'reduction of pressure. insaid pressure chamber.

' 2. In a s gnal controlling means, a doubleended plunger, .twocyhndersrm which the 'endsof said plunger arereceived respectively, oneof said cylinders'havinrg a fluidjn-let' to effect shding'of the'plunger, the "other cylinder constituting an *air trap in "which 'airis compressed 'isaid "sliding "of the plunger, the air ,so'compressedserving to return said plunger.

3. In a' signal controlling means, a' double ended plunger, twocylinders in"wh1ch=the ends of said plunger are received respectively,oneof said "cylinders, hav ng'afiuidin-let to effect sliding oftheplunger, the other cylinder constituting an air'traplin which air iscompressed by sald' sliding of theiplunger .tor use to return saidplunger, and a signal controlling member having a frictional con-''nection with said plunger to be'moved'by the latter to apredeterminedposition and to, then permit further movementof theplunger.

4.111 a signal controlling means, a doubleended plunger, twocylinders'in which the ends of said plungerare'received respectively,one of said cylinders having a fluid inlet to effect sliding of theplunger, the other cylinder constituting an air trap in which air iscompressed by said. sliding of the plunger for use toreturn'saidplunger, and a signal con- ;.ably.:mounted, said cylinder having aninternally enlarged portion receiving a portion of =saidplunger, fixedcontact'means within said enlarged cylinder portion, and a switch memberin said cylinder portion co-operable with said contact means and havinga frictional connection with saidplunger.

'7. In a signal controlling means, a doubleended plunger, two cylindersin which the ends of said'plunger-are'received respectively, oneofisaid'cylinders having a fluid inlet to efiect sliding of the'plunger,the ;othert cylinder constituting an' air trap 1 in :which air: iscompressed by said*sliding of the'plungentor use to return saidplunger,connectin means between the inner ends of said cylinders, fixedcontact means carried'bysaid connecting 7 "means, and a-switch memberco-"operable with esaid contact 'means and "having r a frictionalconnection with said "plunger.

"8. In a signal-control ng means, an; oper- 1 ating member and meansioreliect-ingimove- 'ment there-oi, a "signal-controlling J current-.conducting "contact engagingisWitCh :niemher carried-soh'aly by saidoperating member and having frictional slip connection there with,

enda stationary contact in the path inwhich 1 CHARLES T. MAG'HIL.

